A decision by the U.S. Supreme Court to strike down President Trump’s “emergency” tariffs — a ruling that’s expected to be handed down soon — won’t be the last word on the tariff controversy.

At immediate issue is Trump’s authority to impose tariffs under the International Emergency Economic Powers Act (IEEPA). As the law’s name indicates, it allows the President to take certain actions in the event of a “national emergency” — even though it makes no mention of tariffs as an avenue of relief against imports.

A hearing before the Supreme Court in November found several of the justices expressing skepticism over the President’s self-asserted right to slap tariffs on incoming goods under IEEPA. Should they follow through on that sentiment, however, they’ll raise another issue: how to refund importers for the tariffs they’ve already paid.

Businesses could be owed a collective $168 billion in invalidated tariffs, creating a big administrative headache for U.S. Customs and Border Protection. By law, importers have 180 days from entry liquidation, or final calculation by CBP of duties owed, to file for refunds. Most liquidations occur within 314 days of entry, so for those duties that were finalized early this year, the clock is ticking for importers who want their money back.

It’s uncertain at this point whether the Supreme Court will designate CBP as the agency to process the refunds, or whether the dispute will have to be settled in the Court of International Trade. A number of importers have already filed suit in the CIT, in anticipation of the Supreme Court invalidating the IEEPA tariffs.

Trump imposed that particular set of tariffs on February 1 of this year, prompting some U.S. importers to hold off on bringing additional inventory into the country until the summer, thereby giving themselves more time now to file for refunds, notes Tony Gulotta, principal and practice leader of national tax with the Ryan tax firm. 

For its part, CBP can liquidate whenever it wants, and could respond to an adverse Supreme Court ruling by accelerating all liquidations. “That would put the importer of record in the position of having to do something proactive — either file a protest with CBP, or appeal with the CIT,” Gulotta says. (Appeals to the latter must be filed within two years.)

Gulotta says there’s little precedent for importers demanding duty refunds on such a broad scale. A telecommunications tax was reversed, and businesses reimbursed by the Internal Revenue Service, in the early 2000s, but the amount involved is dwarfed by the potential payback of IEEPA tariffs.

To prepare for refunds, importers must be able to document the actual IEEPA taxes paid, separate from any other levies. “This will be a huge burden for importers,” acknowledges Gulotta. “First, importers of record have to go through a year’s worth of entries, and decide what portion were IEEPA [tariffs] and which were unaffected.”

In the end, a full refund is by no means guaranteed, Gulotta says. CBP might try to hold back some of the funds, or retroactively impose a 15% tariff for 150 days under section 122 of the Trade Act of 1974. That clause grants the President temporary authority to impose tariffs to address “large and serious” deficits in the U.S. balance of payments, or depreciation of the dollar. In addition, Gulotta says, CBP could refuse to pay interest on the money owed to importers.

A Supreme Court ruling on IEEPA will not affect tariffs imposed by Trump under other statutes, including section 232 of the Trade Expansion Act of 1962, section 301 of the Trade Act of 1974, and section 338 of the Tariff Act of 1930. Those laws have higher standards of proof, however, requiring congressional investigations and determination of damage before the imposition of new duties. Nevertheless, importers enjoying relief from the IEEPA tariffs could find themselves slapped with additional fees under those laws.

Regardless of how much money is involved, and which agency or court will ultimately be responsible for handling the IEEPA protests, importers could be in for a drawn-out process. One possible action would be to assign their submitted claims to finance companies, which would take on the burden of pursuing the claims while paying the importers up front at a discount. “The folks I talk to aren’t willing to buy claims right now,” Gulotta says. “It’s like going to a casino. But once you have a decision, then it’s just a finance question.”